Akzeptanz und Nutzererleben von körpergetragenen Assistenzsystemen im industriellen Anwendungsbereich

Der Beitrag beschreibt erlebnisorientierte Aspekte der Entwicklung von körpergetragenen technischen Assistenzsystemen im industriellen Einsatz. Dabei wurde untersucht, wie Akzeptanz für technische Assistenzsysteme entsteht und was die körpernahe Produktinteraktion für das Nutzererleben bedeutet. Neben herkömmlichen Methoden aus der Design- und empirischen Sozialforschung wurden aus der Akzeptanzforschung bekannte Modelle im Hinblick auf Nutzerinteraktion und -erleben untersucht. Die Erkenntnisse können nach Ansicht der Autoren als hilfreicher und allgemein anwendbarer Teil des Entwicklungsprozesses im hoch innovativen technischen Umfeld betrachtet werden

Akzeptanz und Nutzererleben von körpergetragenen Assistenzsystemen im industriellen Anwendungsbereich

Der Beitrag beschreibt erlebnisorientierte Aspekte der Entwicklung von körpergetragenen technischen Assistenzsystemen im industriellen Einsatz. Dabei wurde untersucht, wie Akzeptanz für technische Assistenzsysteme entsteht und was die körpernahe Produktinteraktion für das Nutzererleben bedeutet. Neben herkömmlichen Methoden aus der Design- und empirischen Sozialforschung wurden aus der Akzeptanzforschung bekannte Modelle im Hinblick auf Nutzerinteraktion und -erleben untersucht. Die Erkenntnisse können nach Ansicht der Autoren als hilfreicher und allgemein anwendbarer Teil des Entwicklungsprozesses im hoch innovativen technischen Umfeld betrachtet werden

Key Parameters for the Synthesis of Active and Selective Nanostructured 3d Metal Catalysts Starting from Coordination Compounds – Case Study: Nickel Mediated Reductive Amination

The design of nanostructured catalysts based on earth-abundant metals that mediate important reactions efficiently, selectively and with a broad scope is highly desirable. Unfortunately, the synthesis of such catalysts is poorly understood. We report here on highly active Ni catalysts for the reductive amination of ketones by ammonia employing hydrogen as a reducing agent. The key functions of the Ni-salen precursor complex during catalyst synthesis have been identified: (1) Ni-salen complexes sublime during catalyst synthesis, which allows molecular dispersion of the metal precursor on the support material. (2) The salen ligand forms a nitrogen-doped carbon shell by decomposition, which embeds and stabilizes the Ni nanoparticles on the γ-Al2O3 support. (3) Parameters, such as flow rate of the pyrolysis gas, determine the carbon supply for the embedding process of Ni nanoparticles

Isolated Rh atoms in dehydrogenation catalysis

Isolated active sites have great potential to be highly efficient and stable in heterogeneous catalysis, while enabling low costs due to the low transition metal content. Herein, we present results on the synthesis, first catalytic trials, and characterization of the Ga9Rh2 phase and the hitherto not-studied Ga3Rh phase. We used XRD and TEM for structural characterization, and with XPS, EDX we accessed the chemical composition and electronic structure of the intermetallic compounds. In combination with catalytic tests of these phases in the challenging propane dehydrogenation and by DFT calculations, we obtain a comprehensive picture of these novel catalyst materials. Their specific crystallographic structure leads to isolated Rhodium sites, which is proposed to be the decisive factor for the catalytic properties of the systems

Surface Chemistry of the Molecular Solar Thermal Energy Storage System 2,3-Dicyano-Norbornadiene/Quadricyclane on Ni(111)

Molecular solar thermal (MOST) systems are a promising approach for the introduction of sustainable energy storage solutions. We investigated the feasibility of the dicyano-substituted norbornadiene/quadricyclane molecule pair on Ni(111) for catalytic model studies. This derivatization is known to lead to a desired bathochromic shift of the absorption maximum of the parent compound. In our experiments further favorable properties were found: At low temperatures, both molecules adsorb intact without any dissociation. In situ temperature-programmed HR-XPS experiments reveal the conversion of (CN)2-quadricyclane to (CN)2-norbornadiene under energy release between 175 and 260 K. The absence of other surface species due to side reactions indicates full isomerization. Further heating leads to the decomposition of the molecular framework into smaller carbonaceous fragments above 290 K and finally to amorphous structures, carbide and nitride above 400 K. DFT calculations gave insights into the adsorption geometries. (CN)2-norbornadiene is expected to interact stronger with the surface, with flat configurations being favorable. (CN)2-quadricyclane exhibits smaller adsorption energies with negligible differences for flat and side-on geometries. Simulated XP spectra are in good agreement with experimental findings further supporting the specific spectroscopic fingerprints for both valence isomers

Au-Catalyzed Energy Release in a Molecular Solar Thermal (MOST) System: A Combined Liquid-Phase and Surface Science Study

Molecular solar thermal systems (MOSTs) are molecular systems based on couples of photoisomers (photoswitches), which combine solar energy conversion, storage, and release. In this work, we address the catalytically triggered energy release in the promising MOST couple phenylethylesternorbornadiene/quadricyclane (PENBD/PEQC) on a Au(111) surface in a combined liquid-phase and surface science study. We investigated the system by photoelectrochemical infrared reflection absorption spectroscopy (PEC-IRRAS) in the liquid phase, conventional IRRAS and synchrotron radiation photoelectron spectroscopy (SRPES) in ultra-high vacuum (UHV). Au(111) is highly active towards catalytically triggered energy release. In the liquid phase, we did not observe any decomposition of the photoswitch, no deactivation of the catalyst within 100 conversion cycles and we could tune the energy release rate of the heterogeneously catalyzed process by applying an external potential. In UHV, submonolayers of PEQC on Au(111) are back-converted to PENBD instantaneously, even at 110 K. Multilayers of PEQC are stable up to ~220 K. Above this temperature, the intrinsic mobility of the film is high enough that PEQC molecules come into direct contact with the Au(111) surface, which catalyzes the back-conversion. We suggest that this process occurs via a singlet–triplet mechanism induced by electronic coupling between the PEQC molecules and the Au(111) surface

GOCE’s view below the ice of Antarctica: Satellite gravimetry confirms improvements in Bedmap2 bedrock knowledge

Accurate knowledge of Antarctica's topography, bedrock, and ice sheet thickness is pivotal for climate change and geoscience research. Building on recent significant progress made in satellite gravity mapping with European Space Agency's Gravity field and Ocean Circulation Explorer (GOCE) mission, we here reverse the widely used approach of validating satellite gravity with topography and instead utilize the new GOCE gravity maps for novel evaluation of Bedmap1/2. Space-collected GOCE gravity reveals clear improvements in the Bedmap2 ice and bedrock data over Bedmap1 via forward modeled topographic mass and gravity effects at spatial scales of 400 to 80 km. Our study demonstrates GOCE's sensitivity for the subsurface mass distribution in the lithosphere and delivers independent evidence for Bedmap2's improved quality, reflecting new radar-derived ice thickness data. GOCE and Bedmap2 are combined to produce improved Bouguer gravity maps over Antarctica. We recommend incorporation of Bedmap2 in future high-resolution global topography and geopotential models and its use for detailed geoid modeling over Antarctica